Created with Highcharts 4.2.5Length (in mm)Number of leavesLength (in mm) Vs Number of leaves35912542Length (in mm) Vs Number of leaves117.5-126.5126.5-135.5135.5-144.5144.5-153.5153.5-162.5162.5-171.5171.5-180.5051015144.5-153.5Length (in mm) Vs Number of leaves: 12

Solution (II): Other suitable graphical representation of this data is frequency polygon.

Solution (III): No, maximum number of leaves has in between 144.5 mm and 153.5 mm. It is not necessary that all leaves length as 153 mm.

Q-5 The following table gives the life times of 400 neon lamps:

Life times of neon lamps are shown in tableLife times of neon lamps are shown in table

Life time (in hours)

Number of lamps

300-400

14

400-500

56

500-600

60

600-700

86

700-800

74

800-900

62

900-1000

48

I. Represent the given information with the help of a histogram.

II. How many lamps have a lifetime of more than 700 hours?

Solution (I): Life time of x-axis and the number of lamps on y-axis.

Histogram:

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Created with Highcharts 4.2.5Life time (in hours)Number of lampsLife time (in hours) Vs Number of lamps14566086746248Life time (in hours) Vs Number of lamps300-400400-500500-600600-700700-800800-900900-10000255075100700-800Life time (in hours) Vs Number of lamps: 74

Solution (II):

Lifetime more than 700 is the sum of the number of neon lamps having their lifetime as, and

So, neon lamp having more than 700 hour’s lifetime

Q-6 The following table gives the distribution of students of two sections according to the mark obtained by them:

Distribution of students according to marksDistribution of students of two sections according to marks

Section A

Section B

Marks

Frequency

Marks

Frequency

0-10

3

0-10

5

10-20

9

10-20

19

20-30

17

20-30

15

30-40

12

30-40

10

40-50

9

40-50

1

Represent the marks of the students of both the sections on the same graph by two frequency polygons. From the two polygons compare the performance of the two sections.

Solution:

The class marks of the given class intervals by using the formula.

Class interval (Marks)

Frequency polygons data table of Section A and BFrequency polygons data table of Section A and B